Fastening technologies span a very wide range of methods and materials. Screws, bolts, and rivets are high strength fasteners that focus the stress of separation into concentrated locations. They use relatively high tensile strength materials, and focus the forces of attachment at the points where the fastening is used. Mechanical fasteners, such as hook and loop fasteners and headed stem fasteners, rely on a mechanical interference to attain coupling.
Adhesives (such as pressure sensitive adhesives), glues, and epoxies distribute adhesion forces, but are not refastenable in high strength applications. In many cases they require curing or adhesion dwelling before the ultimate fastening strength is achieved. Generally there is an unmet need for instant high strength fastening, with refastenability where the forces are distributed over a large area. There is also a need to accomplish this using a low profile or thin layer.
Mating surface fasteners are a type of self-mating fasteners. They use intermeshable articles, some of which require alignment before pressing the structured surfaces together (U.S. Pat. No. 4,875,259) and some of which can be fastened in random alignment (U.S. Pat. No. 5,201,101). Other mating surface fasteners are disclosed in U.S. Pat. Nos. 5,344,177 and 5,360,270. Mating surface fasteners do not require a mechanical interference. They use a frictional interaction between adjacent elements.
Mating surface fasteners typically include a series of structured surfaces, such as tapered elements or posts, connected to a sheet, sometimes called a base or land. Two articles can be removably attached to each other by first attaching a mating surface fastener to each article. This is typically performed using an adhesive.
Each tapered element has at least one side inclined relative to a common plane at an angle sufficient to form a taper. The sheets' plurality of tapered elements are situated to form a plurality of axes including at least one longitudinal axis on each sheet. When fastened together, the longitudinal axis of each sheet is at an angle relative to the longitudinal axis of the other sheet. Also, at least one of the tapered elements is axially bent or torsionally flexed or twisted relative to its relaxed, unfastened position. Also, the inclined sides of some of the tapered elements are frictionally adhered to at least some of the inclined sides of the other of the tapered elements to maintain the sheets fastened together. The force used to engage the fasteners on the two articles determines the force required to disengage the fasteners.